1. Field of the Invention
The invention relates to an electromagnetic doorlock, particularly to the electromagnetic doorlock with shock detection and power saving device.
2. Description of the Related Art
In the access control monitoring system, the use of an electromagnetic door lock has been very popular. The electromagnetic door lock 10 as shown in FIG. 1 provides an electric magnet 11 mounted on a door frame 13 and an adsorption plate 12 mounted on a corresponding position of a door plate 14. When the electric magnet 11 is energized to produce electromagnetic attraction and adsorb the adsorption plate 12, the electromagnetic door lock 10 forms in a lock state. When the electric magnet 11 is de-energized and the adsorption plate 12 detaches from the electric magnet 11, the electromagnetic door lock 10 then forms in an unlock state. The above features are disclosed in U.S. Pat. No. 4,352,028.
Normally, the power consumption of the electromagnetic door lock 10 of the DC power is about tens of watts. If 12 volts of DC power is supplied, the consumption current maintains hundreds of mill-amperes (mA); thus, the electromagnetic door lock 10 requires a lot of electrical energy.
It is considerable that the safety monitoring system of the electromagnetic door lock requires practical applicability and controllability; therefore, energy saving design requires further improvement.